number of instances to launch. If this number of instances cannot be launched, no instances will launch. If specified as a range (min-max), the server will attempt to launch the maximum number, but no fewer than the minimum number.

[VPC only] add a network interface to the new instance. If the interface already exists, supply its ID and a numeric index for it, separated by ":", in the form "eni-NNNNNNNN:INDEX". To create a new interface, supply a numeric index and subnet ID for it, along with (in order) an optional description, a primary private IP address, a list of security group IDs to associate with the interface, whether to delete the interface upon instance termination ("true" or "false"), a number of secondary private IP addresses to create automatically, and a list of secondary private IP addresses to assign to the interface, separated by ":", in the form ":INDEX:SUBNET:[DESCRIPT ION]:[PRIV_IP]:[GROUP1,GROUP2,...]:[true|false]:[SEC_I P_COUNT|:SEC_IP1,SEC_IP2,...]". You cannot specify both of the latter two. This option may be used multiple times. Each adds another network interface.